smoke flow jitters around flow source when using adaptive domain #58492

New Issue

Chris heaton · 2018-12-02T03:57:56+01:00

Chris heaton commented

2018-12-02 03:57:56 +01:00

System Information
Operating system: windows 10
Graphics card: nvidia gt970 4gb

Blender Version
Broken: smoke simulation

2.80 beta 0f5b53ba4d

smoke simulation jitters around in the domain when adaptive domain is used instead of flowing naturally.

Exact steps for others to reproduce the error
make a smoke domain from the default cube, and add a new cubemake it smaller and aply the scale. then make it a smoke flow object. set the adaptive domain and bake the sim. on playback/render the smoke moves around the source cube instead of flowing from a fixed position. smoke test.blend

**System Information** Operating system: windows 10 Graphics card: nvidia gt970 4gb **Blender Version** Broken: smoke simulation 2.80 beta 0f5b53ba4dc smoke simulation jitters around in the domain when adaptive domain is used instead of flowing naturally. **Exact steps for others to reproduce the error** make a smoke domain from the default cube, and add a new cubemake it smaller and aply the scale. then make it a smoke flow object. set the adaptive domain and bake the sim. on playback/render the smoke moves around the source cube instead of flowing from a fixed position. [smoke test.blend](https://archive.blender.org/developer/F5785048/smoke_test.blend)

Chris heaton commented

2018-12-02 03:57:56 +01:00

Added subscriber: @Chrisheaton

blender-admin commented

2018-12-02 03:57:56 +01:00

#60488 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#60237 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#59463 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#59252 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#59166 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#58996 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#58826 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#58642 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#58545 was marked as duplicate of this issue

blender-admin commented

2018-12-02 03:57:56 +01:00

#58487 was marked as duplicate of this issue

Martin Felke commented

2018-12-03 13:59:30 +01:00

Added subscriber: @scorpion81

Martin Felke commented

2018-12-03 13:59:30 +01:00

Can confirm the jittering behavior. Last known good commit is e60c49ecf0 from November 25, 2018. (that time i last merged 2.8 into temp-fracture-modifier-2.8, and it works in the branch)
So i am trying to git bisect now from there till HEAD to find the faulty commit... I keep you posted.

Can confirm the jittering behavior. Last known good commit is e60c49ecf06815039137c98f86a7198d6ee81e14 from November 25, 2018. (that time i last merged 2.8 into temp-fracture-modifier-2.8, and it works in the branch) So i am trying to git bisect now from there till HEAD to find the faulty commit... I keep you posted.

Martin Felke commented

2018-12-03 14:49:12 +01:00

And the winner is : 33cbcd7344 from November 26, 2018 , question is how to fix that... hmm

And the winner is : 33cbcd73448fb1cedc083c2b1fb9a27489d09432 from November 26, 2018 , question is how to fix that... hmm

Bastien Montagne commented

2018-12-03 21:05:50 +01:00

Added subscriber: @Crumpley

Bastien Montagne commented

2018-12-03 21:06:15 +01:00

Added subscribers: @Zexyp, @StephenSwaney, @JeannotLandry

Bastien Montagne commented

2018-12-03 21:06:38 +01:00

Added subscriber: @jokershadow

Bastien Montagne changed title from ~~smoke flow jitters around flow source~~ to smoke flow jitters around flow source when using adaptive domain

2018-12-03 21:13:04 +01:00

Brecht Van Lommel commented

2018-12-05 23:02:09 +01:00

Added subscriber: @taraku1991

Bastien Montagne commented

2018-12-06 11:39:20 +01:00

Added subscribers: @fclem, @mont29

Clément Foucault was assigned by Bastien Montagne

2018-12-06 11:39:20 +01:00

Bastien Montagne commented

2018-12-06 11:39:21 +01:00

In fact, I believe this is a drawing issue, probably smoke draw code assuming texspace would be the one of the final evaluated mesh or something like that? Smoke simulation code itself at least is not affected by that afaict, it computes its own bbox…

When adaptive domain is enabled, that bbox is recomputed for every frame, and the 'mesh' domain size adjusted as needed, while for fixed domain it is only computed once (and current drawing with adaptive domain on is not only jittering, it is also clearly over-scaled).

I can look further into this if needed, but maybe it’s simpler for @fclem to first have a look and see if fix is simple from drawcode side (knowing that mesh's texspace should now always be orig mesh one, and no more recomputed from final eval mesh)?

In fact, I believe this is a drawing issue, probably smoke draw code assuming texspace would be the one of the final evaluated mesh or something like that? Smoke simulation code itself at least is not affected by that afaict, it computes its own bbox… When adaptive domain is enabled, that bbox is recomputed for every frame, and the 'mesh' domain size adjusted as needed, while for fixed domain it is only computed once (and current drawing with adaptive domain on is not only jittering, it is also clearly over-scaled). I can look further into this if needed, but maybe it’s simpler for @fclem to first have a look and see if fix is simple from drawcode side (knowing that mesh's texspace should now always be orig mesh one, and no more recomputed from final eval mesh)?

Bastien Montagne commented

2018-12-08 16:13:51 +01:00

Added subscriber: @Facu

Julien Leménicier commented

2018-12-10 11:35:33 +01:00

Added subscriber: @lemenicier_julien

Stephen Swaney commented

2018-12-11 05:08:46 +01:00

Added subscriber: @SeanKennedy

Clément Foucault commented

2018-12-11 18:43:43 +01:00

So this is not a drawing issue. The texspace should be set accordingly for the adaptive domains (which is only valid on the evaluated mesh since it changes size).

So the update need to be propagated down somehow.
However, BKE_object_dimensions_get() does work fine so the actual bounding box is correct.
It seems that the bbox is changed somewhere by the smoke sim.

Also @scorpion81 said on IRC that the texspace is used indirectly by the transform code and that it also behaves strangely.

So this is not a drawing issue. The texspace should be set accordingly for the adaptive domains (which is only valid on the evaluated mesh since it changes size). So the update need to be propagated down somehow. However, BKE_object_dimensions_get() does work fine so the actual bounding box is correct. It seems that the bbox is changed somewhere by the smoke sim. Also @scorpion81 said on IRC that the texspace is used indirectly by the transform code and that it also behaves strangely.

Bastien Montagne commented

2018-12-11 19:12:02 +01:00

Well, in most cases we want to keep texspace from orig mesh (i.e. not take into account changes from modifier stack). Otherwise, you get fluctuating texturing when modifiers change bounds of the geometry. So question here is: do we want/need to make an exception for domain of smoke sim (and maybe others? Though iirc fluid e.g. generated geometry, not a 3D texture…)?

Clément Foucault was unassigned by Bastien Montagne

2018-12-11 19:12:41 +01:00

Bastien Montagne self-assigned this 2018-12-11 19:12:41 +01:00

Brecht Van Lommel commented

2018-12-12 16:36:11 +01:00

Added subscriber: @mythcat

Bastien Montagne commented

2018-12-17 10:45:51 +01:00

Added subscriber: @TheCharacterhero-4

Bastien Montagne commented

2019-01-06 18:09:51 +01:00

Added subscriber: @Iago-Diogo-de-Vasconcelos-Mota

Bastien Montagne commented

2019-01-14 10:16:09 +01:00

Added subscriber: @NathanWondrak

Carlo San commented

2019-01-19 00:57:07 +01:00

Added subscriber: @Carlosan

Carlo San commented

2019-01-19 01:00:32 +01:00

Is this bug a regression related to this issue ?
https://developer.blender.org/T43061

Is this bug a regression related to this issue ? https://developer.blender.org/T43061

blender-admin commented

2019-01-22 21:49:38 +01:00

This issue was referenced by 3891ad8e03

This issue was referenced by 3891ad8e03176d993b8082292638117a2963f931

Bastien Montagne commented

2019-01-22 21:52:52 +01:00

Changed status from 'Open' to: 'Resolved'

Bastien Montagne closed this issue

2019-01-22 21:52:52 +01:00

Bastien Montagne commented

2019-01-22 21:53:51 +01:00

I’ve already spent way too much time on this, with very little real result so far.

I am pretty sure that smoke simulation code itself is not affected, afaict before/after 33cbcd7344 we have the same result on simulation itself.

Also, 33cbcd7344 is only revealing the problem, before that commit you can get exact same bug by disabling auto texspace in mesh options (for the domain one).

So I would suspect something wrong going with pointcache (and/or the way it is used by the renderers), but am really, like really not familiar with this code. For now, I'll hack a workaround re-enabling autotexspace (and even forcing it) on domain mesh generated by smoke sim process, that will at least cure the symptoms, in lack of medicine for the illness itself...

I’ve already spent way too much time on this, with very little real result so far. I am pretty sure that smoke simulation code itself is not affected, afaict before/after 33cbcd7344 we have the same result on simulation itself. Also, 33cbcd7344 is only revealing the problem, before that commit you can get exact same bug by disabling auto texspace in mesh options (for the domain one). So I would suspect something wrong going with pointcache (and/or the way it is used by the renderers), but am really, like really not familiar with this code. For now, I'll hack a workaround re-enabling autotexspace (and even forcing it) on domain mesh generated by smoke sim process, that will at least cure the symptoms, in lack of medicine for the illness itself...

Sebastián Barschkis commented

2019-05-20 11:39:22 +02:00

Added subscriber: @sebbas

Sebastián Barschkis commented

2019-05-20 11:39:22 +02:00

Changed status from 'Resolved' to: 'Open'

Sebastián Barschkis reopened this issue

2019-05-20 11:39:22 +02:00

Sebastián Barschkis commented

2019-05-20 11:39:22 +02:00

Think this bug is back - bb88485a16 distorts smoke with the adaptive domain.

It's also present in the Mantaflow branch. I am going to look into this and see if I can find something.

Think this bug is back - bb88485a1693751baff8a61917987323dbee654a distorts smoke with the adaptive domain. It's also present in the Mantaflow branch. I am going to look into this and see if I can find something.

Bastien Montagne removed their assignment 2019-05-20 13:23:07 +02:00

Sebastián Barschkis was assigned by Bastien Montagne

2019-05-20 13:23:07 +02:00

blender-admin commented

2019-05-21 22:07:35 +02:00

This issue was referenced by 1036ae2acd

This issue was referenced by 1036ae2acdea7b0d2988cd458ac5c409905d211f

Sebastián Barschkis commented

2019-05-21 22:23:59 +02:00

Changed status from 'Open' to: 'Resolved'

Sebastián Barschkis closed this issue

2019-05-21 22:23:59 +02:00

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smoke flow jitters around flow source when using adaptive domain #58492